The storage of combustible and flammable liquids such as gasoline, diesel fuel and other similar liquids has long been a problem. With above ground tanks, it has been common to provide a collecting space in the form of a surrounding trench or well which would contain the liquid of the tank in the event of a spill U.S. Pat. No. 3,930,590 to Ebbrell illustrates such a collecting space. There has been no containment in the event of fire in these surrounding trenches.
It is an object of the present invention to provide an above ground storage facility including an inner steel tank for the desired quantity of liquid. A fireproof concrete vault encases the inner tank but provides an annular space between the outside of the inner tank and the inside of the outer tank to serve as a containment volume for any liquid escaping from the steel tank and also as a fire barrier in the event of combustion.
The invention contemplates a unique base construction with a reinforced outer vault and ventilation wall configurations to dissipate condensation. Thus, the tank walls and bottom can remain dry and avoid rusting and corrosion.
A further object is a steel cone roof which encloses the inner tank but also extends over the annular containment volume to prevent entrance of the elements while providing ventilation of the included annular space between the tank and the enclosing vault. Thus, condensation can be dissipated.
The outer vault can be constructed of a selected concrete which has a high resistance to flame and heat as well as bullet proof and may also be constructed of annular vertical sections with sealed joints to enable the height of the overall structure and the resulting volume to be selected for particular needs.
A still further object is the provision of an angled bottom construction with snifter connections and sump evacuations when desired.
Additional objects and features of the invention will be apparent in the following description and claims which, in connection with appended drawings, will enable persons skilled in the art to practice the invention, all in relation to the best mode presently contemplated for the invention.